1. Field of the Invention
The present invention relates to a magnetic recording and reproducing apparatus including a magnetic recording medium and a magnetic head for recording data on the magnetic recording medium. In the magnetic recording medium, portions corresponding to track portions or parts thereof serve as recording areas having a width substantially the same as the width of the tracks, and portions between the recording areas serve as non-recording areas.
2. Description of the Related Art
A significant improvement in the areal density of conventional magnetic recording media such as hard disks has been achieved by, for example, improving the material used to form the recording layer and improving the precision of head processing.
In a magnetic recording and reproducing apparatus including a magnetic recording medium of the perpendicular recording type and a magnetic head of the perpendicular recording type for recording data on the magnetic recording medium, the areal density is increased by orienting magnetic particles such that their magnetization direction is perpendicular to the surface of the medium. This type of magnetic recording and reproducing apparatus has become widespread.
Moreover, magnetic recording media have been proposed in which portions corresponding to track portions or parts thereof serve as recording areas having a width substantially the same as the width of the tracks and in which portions between the recording areas serve as non-recording areas.
For example, magnetic recording media such as discrete track media and patterned media have been proposed (see, for example, Japanese Patent Application Laid-Open No. 2006-048860). In the discrete track media, the recording layer is formed in a concavo-convex pattern corresponding to a track pattern, and the convex portions of the recording layer serve as the recording areas having the shape of the track portion. In the patterned media, convex portions of the recording layer serve as the recording areas having a shape formed by circumferentially dividing track portions.
Moreover, other magnetic recording media have been proposed in, for example, Japanese Patent Application Laid-Open Nos. 2006-286085 and 2002-359138. In these magnetic recording media, portions corresponding to the recording areas or non-recording areas in the recording layer are subjected to ion injection treatment or treatment using a reaction gas to thereby divide the recording layer into non-recording areas in which the saturation magnetization is substantially zero and into recording areas in which the saturation magnetization is non-zero.
When the non-recording area is present between the recording areas as described above, incorrect recording of information on a recording area adjacent to a target recording area, crosstalk between adjacent recording areas, and the like are expected to be suppressed. With the technologies described above, a further improvement in the areal density is expected in the future.
In high areal density magnetic recording media such as magnetic recording media of the perpendicular recording type, it is believed that it is preferable to use a material with a large anisotropic magnetic field as the material for the recording areas. The use of a material with a large anisotropic magnetic field as the material for the recording areas can suppress incorrect recording of information on a recording area adjacent to a target recording area.
However, as the areal density of a magnetic recording medium increases, the width of the magnetic pole of the magnetic head decreases, and therefore the intensity of the recording magnetic field applied from the magnetic head to the magnetic recording medium tends to decrease. Therefore, a magnetic signal may not be recorded in its target recording area when a material with a large anisotropic magnetic field is used as the material for the recording areas and the intensity of the recording magnetic field decreases as described above.
For example, the intensity of the recording magnetic field can be increased by increasing the width of the magnetic pole of the magnetic head. However, in such a case, a magnetic signal can be incorrectly recorded in a recording area adjacent to the target recording area.